WALT (weighted average lease term) is the average time left on a building's leases, with each lease weighted by its rent or its area, so large tenants count more than small ones. A spreadsheet handles the math for one asset and lease-by-lease cash flow software tracks it across a portfolio; Titleman computes it inside a deal underwriting from the rent roll, with each input traced to its source.
Updated 19 October 2026. Published by Titleman, which makes one of the tools compared.
The formula
WALT by rent = Ξ£ (remaining term of each lease Γ its annual rent) Γ· Ξ£ annual rent
Swap rent for square feet to get WALT by area. Vacant suites are left out.
A three-tenant example
For example, an illustrative 20,000 sf building:
| Tenant | Area | Annual rent | Years left |
|---|---|---|---|
| A | 10,000 sf | 300,000 | 8.0 |
| B | 5,000 sf | 125,000 | 2.0 |
| C | 5,000 sf | 100,000 | 0.5 |
By rent: (300,000 Γ 8 + 125,000 Γ 2 + 100,000 Γ 0.5) Γ· 525,000 = 2,700,000 Γ· 525,000 = 5.1 years.
By area: (10,000 Γ 8 + 5,000 Γ 2 + 5,000 Γ 0.5) Γ· 20,000 = 92,500 Γ· 20,000 = 4.6 years.
To break. Suppose tenant A can terminate at year 3. Then (300,000 Γ 3 + 250,000 + 50,000) Γ· 525,000 = 2.3 years. Same building, same rent roll, and the headline drops by more than half. That is the number to ask a seller for when an OM quotes only WALT to expiry.
What WALT hides
One average can mask a large share of rent expiring in one year, so read it next to the expiry schedule. A long lease below market rent is stable income and a cap on upside. Ten years left with a weak tenant is not ten years of income. And WALT is only as good as the rent roll behind it.
Tools for the job
| Option | Best for | What it does | Where it stops | Pricing model |
|---|---|---|---|---|
| Spreadsheet | One asset, a short rent roll | SUMPRODUCT on term and rent | Options and dates entered by hand | Staff time |
| Lease-by-lease cash flow software | Institutional models and portfolios | WALT and expiries from each modeled lease | Inputs maintained by someone | Software license |
| ChatGPT-style general assistant | Explaining the formula, one lease pasted in | Text and formulas | No check against the leases or T-12 | Per-seat subscription |
| Titleman | WALT on a deal or refinance | Reads the rent roll inside an underwriting, ties it to the T-12, returns live Excel | Not a portfolio monitor | Credits per run; ask on a demo |
Where Titleman fits
Send the OM, rent roll and T-12 and ask for WALT by rent, by area and to break. The underwriting returns a memo and a live Excel model where every input shows its source and date and every result shows its formula; missing items, such as an option date the rent roll does not give, are named rather than guessed. The median underwriting took about 58 minutes on production runs in the 30 days to 18 October 2026. If you have the leases, lease abstraction returns each one as 16 fields with the page each came from, which is how you catch the termination option that changes WALT to break.
FAQ
How do you calculate WALT?
Multiply each lease's remaining term by its annual rent, add the results, and divide by total annual rent. For WALT by area, use square feet.
Should WALT be weighted by rent or by area?
By rent for income at risk, which lenders and buyers usually mean; by area for space to re-lease. Say which, because they can differ by years.
What is WALT to break?
WALT to the earliest date each tenant can leave, such as a termination option, rather than to expiry. It is the more cautious figure.
Does Titleman calculate WALT?
Ask for it in the underwriting brief and it comes back as a formula on the rent roll in the live Excel, each input traced to its source.
Next: the best way to track lease rollover risk with AI, how to read a rent roll and AI real estate underwriting software. The method lease by lease: lease rollover risk modeling. To see it on a deal, request a demo.